In recent years, a mobile communication system called “W-CDMA (Wideband-Code Division Multiple Access)” based on a CDMA (Code Division Multiple Access) technology has been proposed by the 3GPP (3rd Generation Partnership Project) and then specified in Non-Patent Document 1.
FIG. 1 shows a typical configuration example of the W-CDMA mobile communication system. As shown in FIG. 1, the mobile communication system includes: radio base stations (NodeBs) each provided with a radio communication function to perform radio communications with mobile stations (UEs: User Equipments) each provided with a radio communication function; radio controller apparatuses (RNCs: Radio Network Controllers) each connected to a corresponding one or more of the radio base stations and performing a radio control operation; and a switching center (MMS: Multimedia Messaging Service) connected to the radio controller apparatuses and performing a switching operation.
As shown in FIG. 1, communications between a mobile station 01 and a mobile station 02 are achieved in the mobile communication system by the aforementioned radio base stations, radio controller apparatuses and switching center.
Here, a network including a radio base station and a radio controller apparatus is called a “Radio Access Network (RAN)”, and a network including a switching center is called a “Core Network (CN)”.
Note that, although the core network includes an apparatus other than the switching center, a description of the apparatus is omitted in this description since the description thereof is not necessary for explaining the present invention.
In the mobile communication system shown in FIG. 1, a radio base station 01 serves cells 01 and 02, a radio base station 02 serves cells 03 and 04, and a radio base station 03 serves cells 05 and 06.
Here, each radio base station serves multiple cells, and is capable of continuing communications of a mobile station by switching the radio link to another when the mobile station moves between the cells.
Note that, the radio controller apparatus performs mobile control processing between the cells by switching the radio link as described above, and performs radio link assignment control processing.
Here, referring to FIG. 2, a description will be given of a call setting procedure between the mobile station 01 and a radio controller apparatus 01, which is performed by a call from the mobile station 02 to the mobile station 01, in the mobile communication system shown in FIG. 1.
As shown in FIG. 2, in step S1401, a switching center 01 notifies, to the radio controller apparatus 01, a call setting instruction for the mobile station 01 located in the cell 01, by use of an “RAB Assignment Request message” on an RANAP (Radio Access Network Application Part) signal.
In step S1402, the radio controller apparatus 01 transmits, to the radio base station 01, a “Radio Link Setup Request message” on an NBAP (NodeB Application Part) signal.
In step S1403, the radio base station 01 performs a setting to transmit user data addressed to the mobile station 01 from the cell 01. In step S1404, the radio base station 01 transmits, to the radio controller apparatus 01, a “Radio Link Setup Response message” on the NBAP signal.
In step S1405, the radio controller apparatus 01 transmits a “Radio Bearer Setup message” on an RRC (Radio Resource Control) signal to the mobile station 01.
In step S1406, the mobile station 01 performs a setting to receive the user data transmitted from the cell 01. In step S1407, the mobile station 01 transmits, to the radio controller apparatus 01, a “Radio Bearer Setup Complete message” on the RRC signal.
In step S1408, the radio controller apparatus 01 determines whether or not the setting of radio access bearers with the mobile station 01 is normally completed. When determining that the setting of the radio access bearers with the mobile station 01 is normally completed, in step S1409, the radio controller apparatus 01 notifies, by use of an “RAB Assignment Response message” on an RANAP signal, the switching center 01 that the setting of the radio access bearers with the mobile station 01 is normally completed.
Likewise, the mobile station 02 also performs the call setting processing, and user data is forwarded in the order of the mobile station 01, the radio base station 01, the radio controller apparatus 01, the switching center 01, the radio controller apparatus 02, the radio base station 02 and the mobile station 02, or in the order reverse to this.
In addition, transmission and reception processing of signals between a switching center and a radio controller apparatus in the mobile communication system shown in FIG. 1 and specified in Non-Patent Document 1 is specified in Non-Patent Document 2.
Here, Non-Patent Document 2 specifies that an “SAI (Service Area Identity)” is exchanged as the location information of a mobile station between the switching center and the mobile station.
Thus, the switching center can perform charging control processing that allows call charges and communication charges to be variable for each service area (cell, for example) by determining the SAI and subscriber information (registration information) in combination, the subscriber information registered by the switching center.
As shown in FIGS. 3 through 6, Non-Patent Document 2 specifies four patterns of the charging control processing. Any of the patterns employs a configuration in which the radio controller apparatus 01 notifies the switching center 01 of the SAI by use of an RANAP signal.
In the example of FIG. 3, the radio controller apparatus 01 notifies the switching center 01 of the SAI in accordance with a request from the switching center 01. In examples shown in FIGS. 4 through 6, the radio controller apparatus 01 notifies the switching center 01 of the SAI without involving a request from the switching center 01.
In addition, Patent Document 1 discloses a technique in which the radio controller apparatus 01 in advance registers identification information (registration information) of a mobile station allowed to perform communications in units of cells controlled by the radio controller apparatus 01, and determines whether or not to allow communications with a specific mobile station located in a particular cell, with reference to the registration information retained in the radio controller apparatus 01, in accordance with a call setting instruction.
Non-Patent Document 1: 3GPP Technical Specification T521.101
Non-Patent Document 2: 3GPP Technical Specification TR25.413
Patent Document 1: Japanese Patent Application Publication 2005-109570